Abstract

We propose a mesoscopic kinetic-inductance radiation detector based on a long superconductor-normal metal-superconductor Josephson junction. The operation of this proximity Josephsonsensor relies on large kinetic inductance variations under irradiation due to the exponential temperature dependence of the critical current. Coupled with a dc superconducting quantum interference device readout, the PJS is able to provide a signal to noise (S/N) ratio up to in the terahertz regime if operated as calorimeter, while electrical noise equivalent power as low as at can be achieved in the bolometer operation. The high performance together with the ease of fabrication make this structure attractive as an ultrasensitive cryogenic detector of terahertz electromagnetic radiation.

Received 18 February 2008Accepted 24 March 2008Published online 22 April 2008

Acknowledgments:

The authors thank the NanoSciERA “NanoFridge” project and the Academy of Finland for financial support. This work has been partially supported by MIUR, PRIN 2006, under the project Macroscopic Quantum Systems-Fundamental Aspects and Applications of Non Conventional Josephson Structures.